Commit 9c1fcdcc authored Jun 05, 2013 by Doug Anderson Committed by Olof Johansson Jun 07, 2013

ARM: exynos: add debug_ll_io_init() call in exynos_init_io()



If the early MMU mapping of the UART happens to get booted out of the
TLB between the start of paging_init() and when we finally re-add the
UART at the very end of s3c_init_cpu(), we'll get a hang at bootup if
we've got early_printk enabled.  Avoid this hang by calling
debug_ll_io_init() early.

Without this patch, you can reliably reproduce a hang when early
printk is enabled by adding flush_tlb_all() at the start of
exynos_init_io().  After this patch the hang goes away.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

parent fb565ff7

arch/arm/mach-exynos/common.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -386,6 +386,8 @@ int __init exynos_fdt_map_chipid(unsigned long node, const char *uname,

		void __init exynos_init_io(struct map_desc *mach_desc, int size)
		{
		debug_ll_io_init();

		#ifdef CONFIG_OF
		if (initial_boot_params)
		of_scan_flat_dt(exynos_fdt_map_chipid, NULL);